Field of the Invention
The present invention relates to intramedullary nails, nail combinations, and bone screws for tibiotalo fusion and talo-calcaneal fusion or distraction as desired. The implant contains particular threading and diameter configurations to achieve selectively both fusion or distraction of the ankle joint within the bare foot.
Description of Related Art
Dual-thread screws, also known as Herbert screws, are known in the art and include end threads as well as head threads, with the head threads having a finer pitch than the end threads. Such a dual-thread screw functions as a compression screw to fixate bone fractures and to fuse joints. A conventional dual-thread screw is shown in FIG. 1. Dual thread screws can be solid or cannulated. Intramedullary nails are known in the art and consist of a solid rod inserted inside a long bone, e.g., the tibia or a metatarsal shaft, and with variously oriented holes for fixating the rod to the host bone. However, conventional compression screws exert compression over the entire length of the shaft, leaving a need for intramedullary nail and screws combinations that provide for more particularly engineered compression.